M365 Mail Connector Setup Failure

I had a domain connected and working. Out of idle curiosity, I hit the test button on the M365 Mailflow page associated with one of my domains. After running for a while, it reported the test failed and changed the domain status to disconnected. The reconnect button now produces an error with a red X after signing in, the error reads "Mailflow Rules not configured. Please try again." On the O365 side I can see the rules have been created then deleted. I deleted the domain from the Mailflow settings and now cannot add it back.